diff options
Diffstat (limited to 'doc/fconfigure.n')
| -rw-r--r-- | doc/fconfigure.n | 63 |
1 files changed, 61 insertions, 2 deletions
diff --git a/doc/fconfigure.n b/doc/fconfigure.n index d903b55..16b81ad 100644 --- a/doc/fconfigure.n +++ b/doc/fconfigure.n @@ -4,7 +4,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: fconfigure.n,v 1.7.2.1 2003/04/18 00:32:34 dkf Exp $ +'\" RCS: @(#) $Id: fconfigure.n,v 1.7.2.2 2004/10/27 12:52:40 dkf Exp $ '\" .so man.macros .TH fconfigure n 8.3 Tcl "Tcl Built-In Commands" @@ -192,7 +192,6 @@ during either input or output. This mode is typically used on UNIX platforms. .RE .PP - .SH "STANDARD CHANNELS" .PP The Tcl standard channels (\fBstdin\fR, \fBstdout\fR, and \fBstderr\fR) @@ -202,6 +201,66 @@ will also support any special option according to their current type. If, for example, a Tcl application is started by the \fBinet\fR super-server common on Unix system its Tcl standard channels will be sockets and thus support the socket options. +.SH EXAMPLES +Instruct Tcl to always send output to \fBstdout\fR immediately, +whether or not it is to a terminal: +.CS +\fBfconfigure\fR stdout -buffering none +.CE +.PP +Open a socket and read lines from it without ever blocking the +processing of other events: +.CS +set s [socket some.where.com 12345] +\fBfconfigure\fR $s -blocking 0 +fileevent $s readable "readMe $s" +proc readMe chan { + if {[gets $chan line] < 0} { + if {[eof $chan]} { + close $chan + return + } + # Could not read a complete line this time; Tcl's + # internal buffering will hold the partial line for us + # until some more data is available over the socket. + } else { + puts stdout $line + } +} +.CE +.PP +Read a PPM-format image from a file: +.CS +# Open the file and put it into Unix ASCII mode +set f [open teapot.ppm] +\fBfconfigure\fR $f \-encoding ascii \-translation lf + +# Get the header +if {[gets $f] ne "P6"} { + error "not a raw\-bits PPM" +} + +# Read lines until we have got non-comment lines +# that supply us with three decimal values. +set words {} +while {[llength $words] < 3} { + gets $f line + if {[string match "#*" $line]} continue + lappend words [eval concat [scan $line %d%d%d]] +} + +# Those words supply the size of the image and its +# overall depth per channel. Assign to variables. +foreach {xSize ySize depth} $words {break} + +# Now switch to binary mode to pull in the data, +# one byte per channel (red,green,blue) per pixel. +\fBfconfigure\fR $f \-translation binary +set numDataBytes [expr {3 * $xSize * $ySize}] +set data [read $f $numDataBytes] + +close $f +.CE .SH "SEE ALSO" close(n), flush(n), gets(n), open(n), puts(n), read(n), socket(n), |